Notes, summaries, assignments, exams, and problems for Biology

Chapter 7 (Sections 1, 2, and 3)

Nutrition: The Science or Study of Food and the Ways in Which the Body Uses Food

Nutrients: Substances in Food that Provide Energy or Help Form Body Tissues and Are Necessary for Life and Growth

Carbohydrates: Class of Energy-Giving Nutrients that Includes Sugar, Starches, Fiber, and Glycogen

Fats: Class of Energy-Giving Nutrients and Are the Main Form in Which Energy Is Stored in the Body

Proteins: Class of Energy-Giving Nutrients Made Up of Amino Acids Which Are Needed to Build and Repair Body Structures and to Regulate Processes in the Body

Glycogen: Made in the Body Which Is Made of Many Glucose Units Linked Together Stored in the Muscle and Liver of Human and Animals Can Be Broken Down to Provide a Quick Source

• In the case of partial injuries, some sensation and movement may be retained below the level of the injury.

• In complete injuries, there is a loss of sensation and total muscular paralysis below the level of the injury

• Depression is a mental illness that often takes the form of low mood and an inability to lead a normal life

Essential Nutrients: A Comprehensive Guide

1. Six Classes of Nutrients

• Carbohydrates (provide energy)
• Fats (provide energy)
• Proteins (provide energy)
• Vitamins (do not provide energy)
• Minerals (do not provide energy)
• Water (does not provide energy)

2. Functions of Carbohydrates, Proteins, and Fats

Carbohydrates

Carbohydrates are broken down into glucose, which is the body's main source of energy. They are important for the brain, nervous system, kidneys, and muscles. Carbohydrates are stored in the liver and muscles for later use as energy. Fiber, a type of carbohydrate, promotes bowel health by allowing waste to move more quickly through the gut. Carbohydrates are found in grains, fruits, milk, nuts, seeds, beans, and vegetables.

Proteins

Proteins build... Continue reading "Essential Nutrients: A Comprehensive Guide to Macronutrients, Micronutrients, and Their Functions" »

Essential Biological Definitions: Blood, Systems, and Pathology

Blood Components and Characteristics

Chordae Tendineae: "Heart Strings"

These are fibrous cords that connect the papillary muscles to the cusps of the atrioventricular valves (mitral and tricuspid valves) in the heart.

Erythrocytes (Red Blood Cells)

The primary function of erythrocytes is oxygen transport.

Leukocytes (White Blood Cells)

Leukocytes are crucial components of the immune system, defending the body against infection and disease.

Granulocytes

Their cytoskeleton contains visible granules.

Agranulocytes

The cytoskeleton lacks granules. There are two main kinds:

• Lymphocytes: Possess large spherical nuclei.
  • T Lymphocytes: Found primarily in the lymph; they attack tumor cells.
  • B Lymphocytes:

Components of the Alpha-Ketoglutarate Dehydrogenase Reaction

1. CoA (Coenzyme A)
2. NAD⁺
3. α-Ketoglutarate Dehydrogenase Complex
4. NADH + H⁺
5. CO₂
6. α-Ketoglutarate
7. Succinyl CoA

Identifying the Reaction

The following components are involved in the reaction catalyzed by Citrate Synthase:

1. Oxaloacetate
2. Citrate
3. Acetyl CoA
4. Citrate Synthase (Enzyme)

The Acetyl Radical of Acetyl-CoA

What is the role of the acetyl radical of Acetyl-CoA?

The Role of Acetyl CoA in the Krebs Cycle

Acetyl CoA is essential for the Krebs cycle (Tricarboxylic Acid Cycle) to occur. It reacts with Oxaloacetate to start the cycle.

During the cycle, 2 CO₂ and 3 NADH + H⁺ are produced (per Acetyl CoA molecule entering the cycle). Specifically, the production of NADH and CO₂ occurs:

• 1 CO₂ and 1 NADH + H⁺ are

Which Nerve Slows the Heart Down?

The Vagus Nerve

Function of Heart Valves

Heart valves ensure one-way blood flow.

Atrioventricular Valves

• Tricuspid valve (3 cusps): Located between the right atrium and right ventricle.
• Bicuspid (mitral) valve (2 cusps): Located between the left atrium and left ventricle.
• Chordae Tendineae: Also known as 'heart strings'.

Semilunar Valves

• Pulmonary semilunar valve: Directs blood from the right ventricle to the pulmonary trunk.
• Aortic semilunar valve: Directs blood from the left ventricle to the aorta.

Arteries vs. Veins

Arteries carry oxygenated blood away from the heart to the body, while veins carry oxygen-poor blood back from the body to the heart.

Three Functions of Blood

Blood has three main functions:

1. Transportation:

1. Human Beings and Health

The World Health Organization (WHO) defines health as 'the complete physical, mental and social well-being, not only the absence of disease'.

The Environment

Healthy surroundings should be free of biological, physical or chemical elements that are harmful to your health.

Personal Characteristics

Genetic factors, age and gender predispose people to suffer from certain types of illnesses.

Lifestyle

Healthy habits and lifestyles are very important for staying healthy.

Healthcare

It is essential to have an efficient healthcare system to guarantee public health.

Vital Signs

Vital signs are physiological parameters that inform us of our state of health or the evolution.

Cause -> Organic Alteration -> Symptoms and Signs ->

Nutrients and Life Stages

The quantity of nutrients that our body needs depends on the stage of life we are in.

• Breastfeeding (0–6 months): Requires breast milk.
• Childhood: Diet gradually becomes similar to an adult diet. Children generally require more calories for growth.
• Adolescence: Nutritional needs are similar to adults.

Nutritional Needs During Adulthood

Specific needs apply, especially during pregnancy. Pregnant women require approximately 300 kcal more per day, increased proteins, specific vitamins (e.g., folic acid), minerals (e.g., calcium), water, and fiber.

Nutritional Needs in Old Age

Older adults generally require similar nutrients to adults, but fewer calories overall.

Macronutrient Distribution and Calories

Recommended Daily Allowance... Continue reading "Essential Health Metrics: Nutrition, Diagnosis, and Disease Facts" »

Origin of Life and Biological Evolution

Theories on Spontaneous Generation

Early experiments tested the concept of spontaneous generation:

• Francesco Redi: Rejected spontaneous generation.
• John Needham: Supported spontaneous generation (later refuted).
• Louis Pasteur: Rejected spontaneous generation using swan-neck flasks.
• Lazzaro Spallanzani: Rejected spontaneous generation.

Darwin's Observations

Species vary globally, locally, and over time.

Biological Evolution

Evolution is characterized by descent from a common ancestor and adaptation to the environment.

Hierarchy of Life Organization

1. Species
2. Population
3. Community
4. Ecosystem
5. Biome
6. Biosphere

Essential Biomolecules

Biomolecules are the fundamental building components of life.

• Carbohydrates (Carbs)

  Primary source